1. Field of the Invention
The present invention relates to an ink jet applicator which jets ink droplets onto an object.
2. Description of the Related Art
A personal computer or the like is provided with a liquid crystal display. The liquid crystal display includes a color filter in which minute liquid droplets of R (red), G (green) and B (blue) colors are sequentially jetted onto a transparent substrate using an ink jet applicator (refer to Japanese Patent Laid-Open Publication No. 2004-111074).
A light shield is arranged around a periphery of the color filter in order to block back light. A black ink is applied all over the light shield for this purpose, for example.
An ink jet applicator is used to form colored dots on the color filter and to blacken the light shield. The ink jet applicator includes ink jet heads having a plurality of nozzles, and jets inks onto target positions of a transparent substrate by moving the ink jet heads and the substrate.
With the ink jet applicator, a solution is filled into each ink jet head at a normal pressure, so that bubbles are formed in the ink. Such bubbles flow with the solution and accumulate in nozzles. In such a case, a pressure applied to the nozzles by piezoelectric elements will be absorbed by the bubbles, which prevents smooth jetting of the solution.
Further, liquid droplets applied onto the substrate or the like tend to dry when exposed in an open air. In such a case, the solution takes different times to dry at the periphery and center of the substrate. This means that the applied solution will have different levels of thickness.